弓网电弧对航空器仪表着陆系统的电磁干扰影响研究

Research on EMI of Instrument Landing System on Aircraft Caused by Pantograph Arc

为探究电气化铁路产生的弓网电弧对航空器仪表着陆系统的电磁干扰,选取达成铁路复线电分相、锚段关节、普通点等典型位置,针对仪表着陆系统的工作频段,开展了弓网电弧的辐射测试。考虑环境因素,通过距离换算获得各典型位置10m处的弓网电弧辐射强度;应用电磁传播理论,推得电气化铁路垂直穿越航空器下滑道时的电磁骚扰最强点;以信号防护率为评估依据,结合弓网电弧实测数据,进行电磁兼容预测。结果表明,电分相处的电磁骚扰最大,在110MHz处电场强度的峰值检波数据达89.3dBμV/m;航向信号与骚扰场强之差只有9.2dB,低于防护率要求4.8dB。测试结果可为电气化铁路选线和机场选址的合理性和可行性提供技术依据。

To explore the electromagnetic interference caused by pantograph arc of electrified railway to aircraft instrument landing system,a radiation test of pantograph arc was carried out near the phase insulator,overlap and general position of Dazhou-Chengdu railway,with the working frequency of instrument landing system.Considering the environmental factors,the pantograph arc intensity radiation at 10 mof various typical positions was acquired by distance conversion.Based on the theory of electromagnetic propagation,the position of strongest disturbance was derived when the railway crossed the glide path of an aircraft vertically.The electromagnetic compatibility was predicted based on the signal protection ratio and the measured data of pantograph arc.The results show that the maximum electromagnetic disturbance occurred near the articulated phase insulator,with 89.3 dBμV/m of peak detection data of the electric field strength at the frequency of 110 MHz.The difference between localizer signal and the disturbance field strength is only 9.2 dB,4.8 dB above the standard.The results in the paper can provide a technical basis for the consistency and feasibility of the site selection of electrified railway and airport.